Australian researcher discovers giant asteroid impact

Oct 24, 2010

(PhysOrg.com) -- A geothermal energy researcher from the University of Queensland (UQ) has found evidence of a major asteroid impact that occurred more than 300 million years ago in the South Australian outback.

The asteroid, which produced a shock zone at least 80km wide, could be the second-largest asteroid ever found in .

UQ’s Queensland Geothermal Energy Centre of Excellence researcher, Dr Tonguc Uysal, discovered the during his studies of the Cooper Basin, which is a large geothermal energy resource being developed in Australia on the border between Queensland and South Australia.

“I noticed that the quartz grains in the rock had unusual planar deformation features that indicated either it had been exposed to extreme tectonic pressure or a large asteroid impact,” Dr Uysal said.

The rock deformations were confirmed as being the result of an asteroid impact through microscopic examination of the quartz crystals and further laboratory tests conducted by Dr Andrew Glikson, from the Australian National University.

“The results suggest that either a very large asteroid or a cluster of asteroids landed, but we need to do further testing to verify this,” Dr Uysal said.

“The impact of the asteroid triggered a huge explosion and caused the ground water to boil and induce chemical and mineralogy changes in the surrounding rocks.

“This may have resulted in the reconcentration of various heat-producing elements which has made the Cooper Basin such a rich source of geothermal energy today,” he said.

The land surface that the asteroid hit is now buried under layers of sedimentary rock and Dr Uysal thinks the original crater most likely eroded away.

Dr Uysal said further studies of rock samples from drill holes in the Cooper Basin were required to more accurately map the extent of the impact area, which is estimated to be at least 80km wide.

Further research will also allow estimation of the size of the asteroid that caused the impact.

Australia’s largest recorded asteroid impact is at Woodleigh, east of Shark Bay in Western Australia and according to Dr Glikson, the Woodleigh impact structure (120 km in diameter) was produced by an asteroid six to 12 kilometres across, about 360 million years ago.

Dr Uysal and Dr Glikson will present their findings at the Australian Geothermal Energy Conference in Adelaide, 16-19 November 2010.

“The Government has funded the Centre to learn more about the potential of hot dry rocks as a clean energy source and to be able to find evidence of a major asteroid impact during their geothermal research is a bonus discovery,” Mr Robertson said.

Explore further: First eyewitness accounts of mystery volcanic eruption

More information: To read more about their research, see their conference paper at: www.uq.edu.au/geothermal/docs/… GEC2010_Abstract.pdf .

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User comments : 19

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Nik_2213
not rated yet Oct 24, 2010
That's a big whack...

Hopefully, the substructure has survived and can be surveyed. There's not enough known about such impactors, and this has the rare advantage of being on ancient, stable rocks...
TDK
1.6 / 5 (14) Oct 24, 2010
Upvoted for direct link to the original source of the story.
Shootist
2.6 / 5 (5) Oct 24, 2010
Down voted for lack of longitude and latitude.

According to http://impacts.rajmon.cz/, Woodleigh has a diameter of 40km, not 120km. Look to Acraman (Lat = -27.95 Lon = 135.37) and Tookoonooka (Lat = -27.10 Lon = 142.80) at 85km-90km, and 80km respectively as the largest proven Australian impacts.

There is a proposed 500-2000km crater (MAPCIS), located at Lat = -25.3255 Lon = 131.2321).

Database of known, proposed and rejected impact structures: http://impacts.ra...ata.html
nuge
not rated yet Oct 25, 2010
Another positive aspect of the increased mining and energy exploration in Australia is that finds like this could become more common. Good to hear.
beelize54
1 / 5 (11) Oct 25, 2010
The more common asteroid impacts in the past just means, the more common such event could become in the future... Is it really good to hear?
nuge
not rated yet Oct 25, 2010
...yes? Just knowing that more occurred in the past doesn't make it any more or less likely today. Meanwhile, we learn more about asteroid impacts.
marjon
1 / 5 (2) Oct 25, 2010
The more common asteroid impacts in the past just means, the more common such event could become in the future... Is it really good to hear?

Only if AGW is considered more of a danger than an asteroid impact.
Skeptic_Heretic
4.3 / 5 (3) Oct 25, 2010
The more common asteroid impacts in the past just means, the more common such event could become in the future... Is it really good to hear?
Not really accurate. Remember the early universe chornology? Particularly the "early bombardment"?
Only if AGW is considered more of a danger than an asteroid impact.
AGW is considered preventable. You know, like not letting your kids play in traffic vs getting into a car accident with a sleeping driver. You can prevent your kids from playing in traffic, but you have zero control over someone crashing into you and killing your kids.
marjon
1.7 / 5 (7) Oct 25, 2010
All sorts of plans are available to detect and deflect asteroids.
These plans ARE based upon solid, certain physical laws. Not like the speculative AGW mitigation fantasies.
GSwift7
2 / 5 (2) Oct 25, 2010
"The more common asteroid impacts in the past just means, the more common such event could become in the future... Is it really good to hear?

Not really accurate. Remember the early universe chornology? Particularly the "early bombardment"?

Really splitting hairs here, but the actual likelyhood of getting hit by an asteroid remains the same whether we know the odds or not. Currently the odds aren't really known according to people like Schumaker. He thinks that it's most likely that if we do get hit any time soon by an object in the 1 mile size range, it will happen with zero warning. He has a National Geographic show about it that's really interesting, and available for streaming on Netflix.

"AGW is considered preventable"

AGW is debated in terms of magnitude and extent, relative to natural warming. It's preventability is even less agreed upon. Experts who support your view usually give a % likelyhood of your statement being true. Those %'s vary. I think it's fair to say.
Skeptic_Heretic
5 / 5 (1) Oct 25, 2010
AGW is debated in terms of magnitude and extent, relative to natural warming. It's preventability is even less agreed upon. Experts who support your view usually give a % likelyhood of your statement being true. Those %'s vary. I think it's fair to say.
Ok, but I'm not referring to mere co2 emissions when I say AGW or AGCC. I'm referring to change brought on by our activities in total. Which when appropriately studied for impact and rammification can usually be prevented.

I also typically attempt to reserve my opinion on the topic as to whether it is beneficial or detrimental when I speak in general terms about the theory in total.
All sorts of plans are available to detect and deflect asteroids.
These plans ARE based upon solid, certain physical laws. Not like the speculative AGW mitigation fantasies.
So tell me how you'd deflect a comet or fast moving asteroid that you detected within a 1AU distance from the planet. That's right, you can't.
Shootist
3 / 5 (2) Oct 25, 2010
Currently the odds aren't really known according to people like Schumaker.


Like Marley, Eugene Shoemaker (April 28, 1928 – July 18, 1997) has been dead, lo these many years.

However, most sources suggest that the impact rate has been steady, or declining, since LHB 4.1Gy-3.8Gy. Even with the large amount of observational, theoretical, and laboratory data now available, the uncertainties in such estimates remain large. Individual estimates of the frequency of impact on Earth for objects of the same size vary by factors of 5–10×, especially for larger objects. (Compare, e.g., the various estimates of Bottke et al., 1994; Neukum and Ivanov, 1994; Grieve and Shoemaker, 1994.)

French B. M. (1998) Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures.

http://www.lpi.us...-954.pdf
Shootist
3.7 / 5 (3) Oct 25, 2010
The known impacts on Earth suggests 10km craters (500m bolide) are produced approximately every 100,000 years, while 1km craters (50m bolide) are produced every 1600 years.

Remember 70% of the planet is water so, generally speaking, 70% of impacts strike Ocean.
Quantum_Conundrum
3 / 5 (2) Oct 25, 2010
Remember 70% of the planet is water so, generally speaking, 70% of impacts strike Ocean.


Ocean impacts can be as bad or worse than continental impacts, both in terms of immediate human casualties and long term effects, due to run up from mile-high mega-tsunamis capable of jumping entire mountain ranges, which would kill hundreds of millions, or even billions of people, depending on what basin it hits.

An impact on a mid-ocean ridge could trigger a chain reaction of super-eruptions which might last for years, decades, or even centuries before the system is stabilized again.
Caliban
1 / 5 (1) Oct 25, 2010
Just a side note- I read somewhere months ago that at least one of these impact craters was discovered after it was pointed out to a scientist by an Aborigine that their "Dream Time" tradition told of it happening- as I recall, the crater in question was on the order of from 200,000YBP.

This may have even been reported here on Physorg. Sadly, I am feeling too lazy to search for a link.

nuge
5 / 5 (3) Oct 25, 2010
mile-high mega-tsunamis capable of jumping entire mountain ranges, which would kill hundreds of millions, or even billions of people, depending on what basin it hits.

An impact on a mid-ocean ridge could trigger a chain reaction of super-eruptions which might last for years, decades, or even centuries before the system is stabilized again.


It's TRUE, I saw it on "Deep Impact"
marjon
1.8 / 5 (5) Oct 25, 2010
So tell me how you'd deflect a comet or fast moving asteroid that you detected within a 1AU distance from the planet.

So tell me how you plan to keep the global climate in the Godilocks zone?
Please elaborate with verified and tested methodologies that produce guaranteed results.
Skeptic_Heretic
5 / 5 (2) Oct 26, 2010
So tell me how you plan to keep the global climate in the Godilocks zone?
Please elaborate with verified and tested methodologies that produce guaranteed results.
No one is arguing for that. If you can follow along... (I know, hard for you to do while you're searching for the next quote to mine) ... you'll see that I commonly promote understanding of what's going on first and foremost, while recommending we get away from fossil fuels for economic and geopolitical reasons.

Beyond that, go ahead and define the "goldilocks zone", it sounds to me like you're confusing astronomy with climatology, not completely unexpected seeing as how weak your familiarity with "the science" is.
wrpeacock
not rated yet Nov 14, 2010
Does anyone know if the feature in western Australia is impact, volcanic, or geologic, at 500 miles wide I'm betting asteroid.